Metals and Non-Metals CW: 04 - Students should be able to classify substances as metals and non-metals. 1. To classify a substance as an element/ compound/mixture 2. List the properties of a metal and a non-metal 3. Be able to give examples of a metal and non-metal We will learn how to: Classify an element as metal or non- metal Investigate properties of metals and non-metals Describe what an alloy is and give examples Identify the conditions necessary for corrosion What are metals? • The Periodic Table helps us identify metals and non-metals • They can be malleable • Canbehammeredintoshapewithout cracking • They are conductors • Theycanconduct(pass)electricity • They can be ductile • Canbestretchedintowire Examples of Metals Experiment: Metals as Conductors of Heat • All metals are good conductors of heat. • Somemetalsarebetter than others. • We are going to test their heat transfer capabilities. Melting Point of metals • Metalshaveaveryhigh melting point What are non-metals? • These have opposite properties to metals. • They are NOT: • Malleable, • Conductors • Ductile Examples of Non-Metals Experiment: Metals as conductors of Electricity • Metalsaregood conductors of electricity. • Createacircuitandseif the metal in between the crocodile clips allows the electricity to pass through it. • How will we know if the metal is conducting electricity? Comparing Metals and Non-Metals Property Metals Non-Metals Appearance Shiny Dull, often coloured Melting and Boiling Point High Low Strength Strong Weak Malleable Yes No Ductile Yes No Conducts Heat Good Poor Conducts Electricity Good Poor What are Alloys? • AnAlloyisamixtureofmetals. • Amixtureistwoormoreelements combined but NOT chemically bonded. • Alloysaregenerally: • Stronger • LongerLasting • Lessexpensive Research these Alloys: Alloy Composition Uses Bronze Copper and Tin Statues Brass Solder Stainless Steel Pewter Alnico Corrosion of Metals When a metal reacts with water and oxygen a metal oxide forms. • WaterANDOxygenareneededforcorrosion • Astheouterlayersofmetalcorrode,theyfall off leaving layers underneath to corrode. • Eventuallythemetalgetstoothinand disintegrates entirely • Example: • Ironreactswithwaterandoxygento form Iron oxide (Rust) Protecting against corrosion • Metals can be coated with other metals or non-metals to help reduce corrosion. • Iron nails can be coated in zinc, which is called galvanizing. Experiment: Corrosion of Metals • Metals will corrode, but need a special set of circumstances for this to happen. What have we learned? Classify an element as metal or non- metal Investigate properties of metals and non-metals Describe what an alloy is and give examples Identify the conditions necessary for corrosion